Imaging of Arthritis

There are a lot of great books out there that teach "Radiology: A to Z". That is, you learn that given disease A, you can expect to see finding Z. It is handy for a radiologist to know lots of this kind of knowledge. When an imaging study is ordered, the request form will hopefully contain the indication for the study, e.g. "suspected osteoarthritis" or "followup rheumatoid arthriits". For suspected osteoarthritis, we will look for the findings we expect to see with osteoarthritis. When we evaluate a case of known rheumatoid arthritis, we will look for the expected findings for rheumatoid arthritis.

However, often a radiology requisition will be much less specific, e.g. "joint pain - suspect arthritis". In this case, it is up to us to figure out just which type of arthritis we are dealing with. In this situation, A to Z learning is not that helpful. Rather, one needs Z to A learning, in which one learns that a particular finding is only seen in a certain list of disorders. This list is termed the "differential diagnosis". The next step is to compare the differential diagnoses generated by each finding. Hopefully these different lists will overlap in such as way that one ends up with a much shorter list of possibilities - ideally just one disorder.

Our hope, therefore, is to teach you "Arthritis: Z to A". In Part I of this book, we present a basic approach to arthritis imaging that will hopefully lead you inexorably from the findings to a diagnosis.

In Part II of this book, we present a number of case studies in specific joints. The case discussions begin with unknown images with short histories. We then pose a series of questions for you to consider when you analyze these images. Once you have made up your own mind, we will tell you what we thought. We will present our findings, our differential and our final diagnosis. Hopefully, these case studies will cover most of the basic patterns of arthritis that you will see in your clinical practice.